Notes on Classification/Taxonomy

Why Classify?To study the diversity of life, biologists use a

classification system to name organisms &

group them in a logical manner.

Why common names don’t workCommon names vary among languages.

Example:

United Kingdom – Buzzard refers to a hawk

United States – Buzzard refers to a vulture

Red-tailed Hawk Honey Buzzard Turkey Vulture

Another Example:

Dolphin Dolphin

Tursipos truncatus Mahi mahi

Taxonomy – science of classifying living organisms

“Father of Taxonomy” – Carolus Linnaeus

(Swedish Botanist)

• he set up the system we use today

• he recognized species on the basis of structural similarity

• he gave them scientific names made up of Latin words

This system is called binomial nomenclature (two-word naming)

• the first word is the genus (which is always capitalized) and the second is the species

Rosa gallica

• both are underlined or italicized

Example of Binomial NomenclaturePolar Bear is Ursus maritimusUrsus: genus

Ursus contains 5 other kinds of bears

U. maritimus: species The Latin word, maritimus, refers to the sea.

Polar bears often live on pack ice that floats in the sea.

GenusGenus: is a group of closely related species

SpeciesSpecies: Group of similar organisms that can breed and produce fertile offspring

FamilyFamily: Group of genera that share many characteristics

OrderOrder: Group of similar families

ClassClass: Group of similar orders

PhylumPhylum: Group of closely related classes

KingdomKingdom: Largest taxonomic group, consisting of closely related phyla.

Are these animals members of the same species?

X =

horse donkey mule(sterile)

No

In taxonomy, a group or level of organization is called a taxonomic category or taxon.

Organizing the Taxa

DomainKingdom

Phylum

Class

OrderFamilyGenus

Species

All living th

ings

Phylum

Chordata

Class

Mammalia

Order

Carnivora

Family

Ursidae

Genus Ursus

Speciesmaritimus

Kingdom

Animalia

Human ClassificationDomain EukaryaKingdom AnimaliaPhylum Chordata Subphylum VertebrataClass MammaliaOrder PrimatesFamily HominidaeGenus: HomoSpecies: sapiens

Scientific name of man -

Homo sapiens

(wise man)

How to remember:Da King Phillip Came Over For Grape Soda

Domain Kingdom Phylum Class Order Family Genus Species

New Species Video Clips

• Classification (4 min)

• New Species (1 min)

The Three-Domain SystemThere are 3 Domains:

Domain BacteriaDomain ArchaeaDomain Eukarya

There are 6 Kingdoms: (in order from least complex)

EubacteriaProtista

Archaebacteria FungiPlantaeAnimalia

The Three-Domain SystemDomain Bacteria

• Kingdom Eubacteria

Domain Archaea• Kingdom Archaebacteria

Domain Eukarya• Kingdoms Protista, Fungi, Plantae, Animalia

Kingdom Archaebacteria• Unicellular Prokaryote• Cell walls withOUT Peptidoglycan• Autotrophic or heterotrophic• Extremophiles – Love extreme environments

like inside the guts of animals, volcanoes, hydrothermal vents, and hot springs

Archaea Hydrothermal Vent Hot Springs Volcanoes

Kingdom Eubacteria• Unicellular Prokaryote• Cell walls with Peptidoglycan• Autotrophic or heterotrophic• All other bacteria you encounter everyday

E. coli Staphlycoccus Streptococcus Streptococcus

Kingdom Protista

• Unicellular or Multicellular eukaryote• Autotrophic or heterotrophic• Some have cell walls of cellulose and chloroplasts• Live either solitary or in colonies

Amoeba Euglena Paramecium

Video Clip: Amoeba

Kingdom Fungi

• Unicellular or Multicellular eukaryote• Cell walls made of Chitin• Heterotrophs

Yeast Mushrooms

Kingdom Plantae• Multicellular eukaryote• Cell walls made of Cellulose• Contain chloroplasts• Autotrophs• nonmotile

Trees & Grass Moss Venus Fly Trap

Kingdom Animalia• Multicellular eukaryote• NO cell walls or chloroplasts• Heterotrophs• Motile (at least for some part of their life cycle)

Worms Insects Jellyfish Giraffes

3 Domains – 6 Kingdoms

“Tree of Life” Cladogram

Where do viruses go?Viruses: Are particles of nucleic acid, protein,

and in some cases lipids that can reproduce ONLY by infecting living cells.

Viruses are made of a core of either DNA or RNA surrounded by a protein coat - capsid.

These are T4 Bacteriophages

A bacteriophage is a virus which infects

bacteria

Viruses are not considered alive because they don’t have ALL the characteristics of life.

Example: They can’t reproduce independently

These are the Influenza Viruses

Influenza or "flu" is an infection of the respiratory

tract that can affect millions of people every year.

The protein in the capsid “tricks” the host cell into allowing the virus inside

• once inside it takes over, putting the genetic program of the virus into effect

Common diseases caused by viruses:

Polio, measles, AIDS, mumps,influenza, yellow fever, rabies,common cold, cancer

Body cavity - coelom

A coelom is a true, main body cavity that surrounds internal organs

Body Cavities

• it is important in classifying animals and in the study of evolution

Symmetry – general form of an organism

3 basic types: (except in snails and amoeba which are asymmetrical)

Symmetry

1. Spherical – a ball (sphere)

• any axis through the center will divide in half

2. Radial – axes radiate like the spokes of a wheel

3. Bilateral – 2 sided

• axis will divide into similar halves

• one side is a mirror image of the other

Body regions for bilateral symmetry:

dorsal – back or upper surface

ventral – stomach (abdomen) or lower surface

anterior – front end

posterior – hind or rear end (tail, caudal)

medial – towards the midline

lateral - side

proximal – part of the appendage which is attached

distal – part of the appendage which is free

dorsal

ventral

posterior

anterior

mediallateral

proximaldistal

Reproduction

2 types of reproduction:

1. Asexual – the formation of offspring without the fusion of sperm and egg (gametes)

• in most cases, the offspring are genetically identical to the parent

• only needs one organism to produce offspring

Types of Asexual Reproduction

a. Binary fission – genetic material is copied and then distributed to new identical cells

Examples: bacteria and some protists

b. Budding – outgrowth form from the parent that eventually pinch off to form new individual

Examples: yeast and hydra

c. Spore formation – production of many spores from a primary spore cell

Example - fungi

d. Regeneration – the ability to replace lost or injured body parts

Examples – starfish and planaria

2. Sexual – involves the fusion of sperm and egg (gametes)

• offspring are not genetically identical to parents

• two parents are needed to produce offspring